It was easy for coach Barry Trotz to figure where to put newly acquired Mike Fisher in the lineup Saturday, when the 30-year-old center made his Nashville Predators’ debut. He had an opening in the middle of his top line between wingers Sergei Kostitsyn and Martin Erat, because Marcel Goc was out with an upper body injury sustained three nights earlier at Detroit.

Goc’s injury was not serious, though, and indications were that he would play Tuesday when the Predators host the San Jose Sharks.

Additionally, forward Marek Svatos underwent knee surgery on Jan. 24 and was expected to miss two-four weeks, which means he might return at any time. Center Matthew Lombardi has increased his activity of late although his timetable has not been upgraded from indefinite due to the concussion he sustained in the second game of the season. There also remains the possibility that doctors in the league’s substance abuse program could clear Jordin Tootoo to return to action at any time.

“Everybody’s going to have to increase their effort because we’re going to have to start making some hard decisions,” Trotz said. “We’ve had just 20 players or 21 for sort of a long time now. That’s about to change. We’re getting some people who are close to getting healthy.”

The Predators made the first of those decisions Sunday when forward Matt Halischuk was reassigned to Milwaukee, although that one was easy.

Halischuk, 24, spent the majority of the season with the Admirals. He had three points (one goal, two assists) in 11 games for Nashville since being recalled on Jan. 16. He also had a plus-1 rating in a limited role (9:46 average ice time) on the fourth line.

Conversely, Fisher, brought over in a trade with the Ottawa Senators, immediately was thrust into a starring role. He was used in all situations and was second in ice time among the team’s forwards in the Predators’ 5-3 victory over Colorado.

Fisher, Kostitsyn and Erat combined for five points, including a goal and two assists by Erat, and a plus-5 rating.

“We were thinking of putting [Fisher] with [Erat] and Kostitsyn,” Trotz said. “[We thought] that might be a possibility. If not, we had all these combinations.

“Goc has done a great job, and that has been our best line for a long time, so I didn’t really want to blow anything up.”

Now, if Trotz reinserts Goc there, Fisher will have to take someone else’s place on another line. That likely will start a chain reaction that ultimately affects more than one line.

Then, every time another player rejoins the lineup over the remaining eight weeks of the season, there will be more adjustments.

Trotz and his staff cannot afford to make the wrong move.

At the end of play Sunday, Nashville was fifth in the Western Conference, slightly above the middle of a group of eight teams separated by four points, which covered third through 10th place in the standings.

“Guys are going to have to set their egos aside and win some hockey games,” Trotz said. “That’s what it’s about. It’s playoff time right now. Just look at the standings, it’s frightening.”